Heat exchange unit



July 16, 1946. wjH, GEDDES 2,404,168 HEAT EXCHANGE UNI'J.1 Y

-Fi1e April 7, 194:1.4

Patented July 16, 1946 UNITEDl STATES PATENT HEAT NIT Walter II. Guides,A Dayton,` lasls'ignor to United Aircraftlroducts, Ine., Dayton, Ohio, a

corporation of Ohio Appleman hpnl 7, 1943, seal N. `82u53 i lai'ins. l

This invention `felates to heat exchange units, especially for cooling hot, viscous liquids such, for example, as the lubricating oil of internal combustion engines, and has for particular reference to improvements in heatexchange units of the type comprising, generally speaking, a heat exchange portion in the form of a core which is surrounded by a passageway through which the liquid to be cooled iiows prior to entering` the core and through which the liquid may flow in by-passing relationship to the core, in the event thelatter may become obstructed to flow of the liquid therethrough due to congelation of the liquid therein or to any other cause. Y i

One well known form of heat exchange unit of the type referred to and with which the vpresent invention is concerned, comprises a casing enclosing the heat exchange core portion ofthe unit, anda jacket surrounding said casing. and .pro viding a passageway extending therearound. The jacket is provided at a suitable point, at the top thereof, for example, with an opening for the inlet to said passageway of the liquid to be cooled,` and the casing is provided at a point diametrieally opposite or substantially diametrically opposite said inlet opening, at the` bottom thereof, for example, with an inlet opening, for flow of liquid into the casing from said passageway. In addition, the casing is provided at a point diametrically opposite or substantially diametrically opposite its inlet opening, at the top'thereotfor example, with an outlet opening for iow of the vliquid therefrom, and the jacket is provided at a suitable point, at the top thereof, for example, with an opening, for outlet of the liquid from said passageway. Normally, however, the. jacket outlet opening is closed by a valve so that the liquid is prevented from flowing in by-passing relationship to thevcore portion of the unit'an-d is required to ow through said core portion. Said valve is, however, maintained normally closed by suitable yieldable means so thatit-may open under a higher-than-normal pressure in the system of` which the unit is apart. Accordingly, ifthe core portion f the unit should,- forany reason,` become obstructed to flow of the liquid therethr'ou'ghl as', for example, due to conglation of the liquid therein, the pressure in the system will riseuntl said yieldably rclosed valve is forced open,` whereupon the liquid will flow in by-'passing relationship to said core portion until the cong'ealed liquid therein has become de-congaled .o'r' such other cause of obstruction to flow' therethrough 2 y Y f will close and flow of the liquid through the core portion of the unit will beV resumed. v

When that portion lof the liquidl in theusystem which is contained in the core portion of the unit is cold and congealed and the remaining, hot portion of the -liquid in the system is owing inbY-passing relationship to said core portion through the passageway surrounding said core being progressively inwardly toward the center ofthe core portion of the unit. y

The initial part of the de-congealing process results in opening of the outer orperipheral part ofthe core portion of the unitA to ow of the liquid therethrough, and when thisr condition is established' flow of the liquidin by"-passingrelationship to said coreportion ceases and is resumed through the said outer or peripheral part of said core portion. However, until all' of the congeal'ed liquid in the core portion'` of the unit has been de-congealed and flow of the liquid through all parts of said core portion has been resumed, the unit does not operate at maximum 'efficiency to maintain the liquid` within a desired temp'era ture range and condition of viscosity best Suiting it to perform its' engine lubricating or 'other function. 0n the contrary, as long as the liquid is circulating inby-passing relation -to the core portion of the unit, or throughl only the outer or peripheral part of the core portion of the unit, it remains too hot. I

In heat 'exchange' units of theA type under con-- sideration it is usual to provide open-ended-tubes extending through the'v core portions of the units for the flow therethrough of air to cool,\the liquid flowing through the core portions. It is also usual to provide shutters to regulate flow vof air through thetubes and to provide meansfwhereby said shutters are actuated in response to variations in the temperature of the liquidy vflowing through'y the core portions of the units. In other words, during normal operation of the heat exchange unit, the shutters are .opened and closed with rise and fall', respectively, of the tempera'- ture of the liquidaboveor below a .predetermined value so that the liquid is Ymaintained within a desired temperaturel range.

y Heretofore, however, the shutters have 'con'- trolled rilow of air throughthe tubes at the outer or peripheral parts of the core portions of f the unitsas well as through the more` inwardly vdisposed tubes, and have prevented iiow of cooling air through the tubes at the outer or peripheral as may exist has been removdl The valve then parts ofthe core portions f the units" until such' desirable that it should be cooled.

Accordinglythe object of the present invention is to provide a heat exchange unit of the type.' under consideration embodying a construction whereby Vthe shutters thereof regulate flow of,V

engine employing a pump, or pumps, for circucooling air through only the more inwardly disposed tubes of the core portion of the unit and do not at any time obstruct flow of cooling air through the tubes at the outer or peripheral part of said core portion, and whereby lcooling air is permitted at all times to flow through the tubes at the outer or peripheral part 'oflsaid corev por-.

in the casing Ii), but in its flow to said housingV is required to pass through said heat exchange core portion. The housing I6 has an opening 20 for outlet of the liquid therefrom regardless of whether the liquid enters said housing through the openings I4, II or I5, I8.

As isunderstood, the present heat exchange unit is to ,be used in a closed-circuit liquid circulating system such, for example, as the lubricant circulating system of an internal combustion lating the vliquid under pressure in the system, and

v .in this, connection it will further be understood tion, thus to insure at least some cooling of the.

intensely hot liquid iiowing around said core"p`ortion in Icy-Passing relationship thereto during times'just prior toresurnption of its flow throughh said core portion following any given period when the liquid in said core portion may have become congealed. Y Y f y With the foregoing and other ,objectsfin view, which'will become more fully apparent as the nature of the invention is better understood, the same consists in a heat exchange unit embodying the novel features of construction, combination and arrangement of parts as will be hereinafter more fully described, illustrated. in the accompanying drawing and defined in the `appended claims. 's I In theaccompanying drawing, wherein like characters of p reference denoteV corresponding parts in the separate views: l v I Figl 1 is an end elevation of a heat exchange unit embodying the features ofthe invention, andi" 1 Fig. 2 is* a vside elevation, partly in` section, of the unit shown in Fig. 1. f

Referring tothe drawing in detail, IIJ designates a casing'which contains the heat exchange core portion yof the present heat exchangeY unit, and I I designatesa jacket surrounding said casing and,v in conjunction'therewith, providing a' passagewayV a extending varound the outside thereof.- The jacket` I I'is provided at a suitable point, at the topV and adjacent to one end-thereof, for example, with anopening I2'for inlet of the liquid I to be cooled'to the. passageway a, while the casing IQ, at a diametrically opposite point, at the bottorn thereof, for example, is provided with an opening' I3 for inlet of the liquid to vsaid casing from the passageway a.' In addition,fthe casing I is' provided at apoint diametrically opposite orfsubstantially diametrically opposite the opening I3,at the top thereof, for example, with an opening I'4 for outlet of the cooled, liquid from said casing, and the jacket I I is provided-at a suitable point, at the top thereof, for example, with an opening I5 for outlet of the liquid from the passageway a'. Y f' 1 l Mounted upon the'ja'cket II in covering'relationship to the outlet openings I4 and vI5 is a housing IISA in the bottom wall of vwhich'are openings I1 and ls which are alined with the openings I4 and I5, respectively, whereby the liquid may iow intov said housing either from the casing I0 vor from the passageway a.' The opening I8 nor- 1 opening 20' ofjthe'housing I6.

that a deliveryvconduit from the engine is connected to the inlet opening I2 and that a return conduit to' theengine is connected to the outlet Return conduit may or may not include a storage tank, air separator-or settling tank.

The valve I9 is closed by suitable yieldable means Vwhich exerts a closing force thereon not materially greater than the opening force which is exerted thereon by thepressure of the liquid in the system during normal operation of the system. Thus, while said valve normally is closedl and requires the liquid to circulate through lthe core portion of the' unit, it may open' and permit circulation of the liquid in by-passing relationship to the core portion of the unit whenever the pressure of the liquid rises above normal. For e'xample, a sudden acceleration of the speed of the engine may produce a pressure of the liquid suiciently high to open said valve, or in the event the liquid in the core portion of the unit should become con-gealed and thereby Vobstruct flow through saidcore portion, the pressure fof the liquid obviously will rise until said valve opens.

In accordance with knownpracticerthe casing I0 has extending' longitudinally therethrough numerous open-ended Y-tubes 2I-r through. which air may flow to cool the liquid circulated through said casing between said'tubes. Also in accordance withA known practice, spaced apart partitions 22 are provided in the casing I0 for cooperation therewith and with each other to require the liquid to flow in atortuous path through said casing so as to be subjected most thoroughly to the coolingeect of the air flowing through the tubes 2|. J

Further in, accordance with known practice, generally speaking, an open-ended casing23 is mounted upon one end of the casing II) and projects therebeyond and has pivotally mounted therein a plurality of shutters 24 to be opened and closed to regulate iiow of cooling air through the tubes 2I.k

Additionally in accordance with known practice, a Athermal power element 25 is mounted in an opening in the housing I6 and has its inner end portion'exposed within said housing at a 1ocation whereit will be affected by the temperature of the liquid when the liquid is circulating through the core portion of the unit and is entering said housing via theropenings I4, I'I.

Inthe housing I6, between the openings Il and I8, is-a partitionl 26 having therein an opening Y2'I controlled byy a check valve 28 to permit the liquid to flowfrom the opening I'I to the housing outlet opening 20, but to prevent Ythe liquid,Y

when itis flowing through the openings I5, I5 andthe housing IB to said housing outlet 'opening 20, from affecting the-thermal element '25,l

The thermal element 25 may be'of any suitable onstmcton'such that @Pali-thereof mQVe' if?. response 'to' 4changes inthe temperature ofv the liquid ilowing over the inner end portion oi said element, and the said movable part of `said'element is connected in any suitable manner with the shutters 24 whereby the latter are opened in harmony with rise in the temperature of the liquid to permit more cooling air to iiow through the tubes 2| and are closed in harmony with lowering of the temperature of the liquid to reduce the amount of cooling air which may flow,

through said tubes.

In the drawing the aforesaid movable part of the thermal element 25 is indicated by way of exiample as comprising a reciprocable stem 29 pro jecting from the outer end of said element, and the connection between vsaidmovable part and the shutters 24 is indicated by way of example as comprising lever arms 30 and 3| connected to the stem 29 and to the shaft lof one of the 'shutters, respectively, and connected together by a rod 32, the shutters being connected together by links 33 so that they are opened andclosed in unison.

As aforesaid, the prior practice has been to employ shutters which regulate flow of air through all parts of the core portions of units of the type illustrated and described, with the disadvantage mentioned. As distinguished from this prior practice and according to the present invention,

the shutters 24 control flow of rcooling air only through such of the tubes 2| as are disposed inwardly o'f the outer or peripheral part of the core portion of the unit and Vprovision is" made for flow of cooling air at all times through the tubes 2| at the outer orperipheral part of the core portion of the unit. In this connection and according toA the speciiic construction illustrated in the drawing, the shutter casing 23 includes a larger diameter inner end portionv 23ab ofapproximately the same diameter as the casing I0 to fit over or into the end of the latter casing, and an outer end portion 23b of materially lesser diameter which contains the shutters 24 and through al1 portions of which flow of air is controlled by said shutters. The two portions 23a, 23D of said shutter casing are joined together by a wall 34 and in this wall is an annular row of openings 35 which are alined, or approximately` alined, longitudinally of the unit, with the tubes 2| at the outer or peripheral part of the core portion of the unit. Thus, some cooling air may ilow through the tubes 2| at the outer or peripheral part of the core portion of the unit regardless of whether' the liquid is flowing through or in by-passing relationship to said core portion and regardless of whether the shutters 24 are open or closed. A

Normally the valve I9 is closed and the hot liquid flows, as indicated by the dash and dot line in Fig. 2, from the inlet opening I2 into the passageway a, through said passageway to the opening I3, into the casing Ill, tortuously through said casing wherein it is cooled by air flowing through the tubes 2|, from said casing through the openings I4 and I1 into the housing I6 and over the inner end of the thermal element whereby its heat causes said thermal element to actuate the shutters 24 to permit the proper amount of cooling air to ow through the tubes 2| to effect proper cooling of the liquid during its flow through the casing I0, and from said housing I6 through the outlet opening 20.

In the event of a sudden acceleration of the speed of the engine such as might produce a surge of the liquid causing the heat exchange core portion of the unit to become choked, or in the event of congelation of the liquid in the .heat exchange core portion of the unit during a period of idleness of the engine, with consequent obstruction to flow of the liquid through said core portion, and upon subsequent starting of the engine, the pressure of thel liquid in the system will rise andthe valve I9 will open. Thereupon, the liquid will follow a path of flow,l as indicated by the dotted lines in Fig. 2, from the inlet opening I2 through the passageway a in by-passing relationship to the heat exchange core portion of the unit contained in the casing I0, through the openings I5 and I8 into the housing I6, through said housing in Iby-passing relationship to the .thermal element 25 due to the provision oi the check valve 28, and from said housing through the outlet opening 20.

Assuming that the liquid in the heat exchange core portion of the unit has become congealed during a periodjof idleness of the engine, that the engine hasbeen started, and that hot lliquid is flowing through the passageway a in by-passing relationship to said heat exchange core portion, it is apparent that the heat of the byepassing liquid will act upon the congealed liquid in the outer or peripheral part of the core portion of the unit to de-congeal the same, whereupon iiow will be resumed through said core portion and the de-congealing process' will progress inwardly until all of the liquid in said core portion has been de-congealed. Heretofore, however, until the by-passing vliquid has acted to de-congeal sufricient of the congealed -liquidin the outer or p`e ripheral part of the core portion of the unit to rei-establish flow through said core portion, and Y even thereafter until suiiicient time had elapsed.

for the' shutters to open, the circulating portion of the liquid remained excessively hot because it was not subjected to any cooling action during its flow through theV heat exchange unit. As distinguished from this, thepresent invention provides for flow of cooling air through the outer or peripheral part of the core portion of the unit at all times. Therefore, eve-n when the hot liquid is flowing in by-passing relationship to the core portion of the unit ,through the passageway a, it is subjected to a certain amount of effective cooling which is increased as lowis resumed through the outer orY peripheral part of said core portion prior to opening of the shutters. It is therefore apparent that the present invention provides for cooling of the intensely hot liquid during the critical .time beginning with initiation of flow of the hot liquid in by-passing relationship to the core portion of the unit and lasting until flow throughl the core portion has been resumed and the shutters 24 have opened.

Thereafter, of course, the cooling is regulated by l the features and the advantages of the invention will be clearly. understood and appreciated. It is desired to point out, however, that while only a single speciiic structural embodiment of the invention has been illustrated and described, the same is readily capable of embodiment in various specically different structures within its annales.

V7 n spirit and scope as Vdefined in the appended claims., f v w n 5 e I claim:

1. A 'heat exchange lunit for use in a closed,-y circuit viscous liquid :circulating system tocool the liquidduring its circulation through the sys,- tem, said unit `comprising va casing having an inlet and anoutletfor the-liquid, means at the peripheral portion and also at the center portionshutter :casing mounted uponsaid iirst -men` tioned casing at one end thereof and extending ybeyond said end thereof, jsaid shutter casing including an inner end portion of substantially the same cross sectional size and shape as said firstI mentioned casing andan outer end'portion of reduced -cross sectional area, a Wall connecting said inner and outer end portions of'said shutter casing and having openings therein for iiowA of cooling air at all times through the ai;` flow` means at the peripheral portion of said first rnen`v tioned casing, shutters in the said outer end portion of .saidl shutter'V casingfor regulating iow` of cooling airthrough thev central portion of said first mentioned casing,-l and means operable in Yresponse to variations Vin the temperature of the l liquidY when itis flowing through said-casing to effect air-flow-regulating actuation of said shutters,r

circuit viscous liquidY circulating system torcool the` liquid during its circulation through the system, said unit comprising a casing havingan` inletand an K, outlet for vthe liquid, open-ended tubes extending longitudinally through the peripheral portion and alsothrough the center D01',-

1 l Y tion of .said casing for ow of air therethrough in cooling relationship lto the liquidV fiowing therethrough, means dening a passageway extending around said casing exteriorly thereof through which the liquid flows to the inlet of said casing, means to cause the liquid vnormally to How through said passageway and said casing and to flow in by-passing relationship to said casing through said passageway when the liquid in said casing is congealed, aeshutter casin-gmounted upon said rst mentioned .casing at vone end thereof and extending beyond lsaid end thereof,"

said shutter casing including an inner endrpor.- tion oi substantially the same cross sectional size and shape as first mentioned casing and an outer 2,15 heat -exchangeunit forvuseV in a closedend portion of reduced cross sectional area, a Wall connecting said inner and outer end portions of saidshutter casing andhaving openings therein for flow of cooling air at alltimes through the tubes in the peripheral portion of said rst mentioned casing, shutters in the said outer end portion of said shutter casing for regulating flow of cooling air through the tubes in the central portion of saidV first mentioned casing, and means operable in response to Variations'in the temperature ofthe liquid when it is flowing through said casing to effect air-,oW-regulating actuation of said shutters. y Y

3. A-n oil temperature regulator for use in engine lubrication systems, comprising a core section made up of a plurality of open ended tubes assembled for the passage of air therethrough as a coolant and for the passage of oil therearound to be cooled, said oil congealing around 'said tubes when excessvely cooled, a casing surrounding said tube assembly and for-med with openings dening ally the central portion thereof, sl'iutterme'ans at one end ofthe regulatorfor controlling the flow of airthrough said core section, a thermostat rel l sponsivevto the temperature of thel oil leaving said core section-for initiating operation of said shutters, said thermostat acting in responseto a rising temperature to Vcause'V movement of said shutters toward open position, andmeans allowing a continuous flow Vof air through the Vperiand said means for allowing a continuous flow of Yair are comprised in a casing extension having Yone end fitted to an end of said casing and having an opposite projecting endv mounting shutters, said. projecting end being-fof reduceddiameter whereby said shutters cover only the centralportion of the core section, and theintermediate area of said extension being .formed with openings aligned Withthe peripheral portion of said core section. Y

l WALTER H. GEDDES. 

